Process for the production of washing bleaching and purification agents

ABSTRACT

A washing, bleaching and cleansing agent containing an active oxygen-containing compound of a salt of boric acid is prepared by adding the active oxygen carrier to a slurry of the active washing substances, washing aids and additives shortly before introduction into a spray drier.

Unite States Patent [72] Inventor Horst Pistor Rhelnfelden (Baden), Germany [21] Appl. No. 793,161 [22] Filed Jan. 22, I969 [45] Patented Dec. 14, 1971 Deutsche Goldund Silber-Scheideanstalt vormals Roessler [73] Assignee Frankfurt am Main, Germany [32] Priority Jan. 24, 1968 [3 3 Germany [31] P 16 92 008.4

[54] PROCESS FOR THE PRODUCTION OF WASHING, BLEACHING AND PURIFICATION AGENTS 10 Claims, No Drawings 52] us. Cl 252/99, Ma /1 W! 11 [51] lnt.Cl Clld 7/56 [50] Field of Search ..252/99, 186

[56] References Cited UNITED STATES PATENTS 2,955,086 10/1960 Hyatt 252/99 3,375,198 3/1968 Rosenfelder 252/99 Primary Examiner-Mayer Weinblatt AuorneyCushman, Darby & Cushman ABSTRACT: A washing, bleaching and cleansing agent containing an active oxygen-containing compound of a salt of boric acid is prepared by adding the active oxygen carrier to a slurry of the active washing substances, washing aids and additives shortly before introduction into a spray drier.

PROCESS FOR THE PRODUCTION OF WASHING, BLEACHING AND PURlFlCATlON AGENTS The invention is directed to a process for the production of a powdered washing, bleaching and cleansing agent, which contains as a bleaching constituent active oxygen compounds of boric acid salts in a largely inseparable form.

For the production of powdered washing, bleaching and purification agents there are used to the greatest extent spray drying processes. According to these processes active washing substance, washing acids and fillers are mixed to a pulp at elevated temperatures, if necessary with the addition of more or less water. This pulp, the so-called slurry, is atomized through a spraying apparatus in a tower where the individual particles become solidified and discharged.

The solidification of the individual particles can take place in two ways. By cold-spraying processes such materials are added to the washing agent composition which crystallize in the airstream at normal temperature with the addition of water. Since these processes largely confine the user in the selection of the washing agent component and a large powdered spray is obtained with a high apparent density preferably there is used a hot spray or spray drying process. According to such process hot air is introduced into the spraying tower, which is allowed to remove excess amounts of water from the atomized slurry and thus to obtain a practically dustfree advantageous spray with a low apparent density.

A special problem occurs in the manufacture of the washing agent in the introduction of the necessary bleaching constituents of active oxygen-containing compounds, especially sodium perborate into the washing agent composition. Since the active oxygen-containing compounds by the action of elevated temperatures and the presence of specific other chemicals are inclined to decompose, the sodium perborate or other active oxygen-containing compounds of the acids of boron are added in general subsequent to the spraying.

if one also can assure through corresponding mixing equipment that the washing agent constituent and sodium perborate will become mixed with each other as uniformly as possible, still there can occur by the presence of unfavorable conditions inhomogeneities in the filled washing agent parcels, which are detrimental to the desired bleaching effect in the use of the washing agent.

It has, therefore, been proposed to combine the sodium perborate with the remaining washing agent components that solid, powdered per compounds are sprayed in the atomization cone of the spray nozzle and there occurs a cementing of individual particles, see German Pat. No. 739,417.

A cementing of the two ingredients accomplished in this manner can certainly lead to a better homogeneity of the resulting wash powder. However, in practice it has the disadvantage that a uniform mixing cannot be attained with certainty and the gluing together of the particles often is not sufficiently hardy against mechanical stress.

It has now been found that it is possible to obtain a washing agent with nearly completely homogenous dispersion of the active oxygen-containing compound if the basic components of the actual active oxygen compounds, which produce the stable portion, are mixed with the slurry, hydrogen peroxide is introduced into the slurry stream as an effective active oxygen carrier shortly before the spray nozzle, and the mixture is dried in the spray tower in the usual manner.

If for example sodium perborate is to be used as the bleaching agent in the washing powder, according to the invention, sodium metaborate is added to the slurry. Surprisingly there is only a slight decomposition of the active oxygencontaining compound in spite of the relatively high temperature of the slurry stream and the temperature at which the mixture is sprayed in the process of the invention.

By addition of known stabilizers to the slurry and/or to the hydrogen peroxide in amounts of 0.3 to 3 percent based on the entire mixture, it is found that practically no decomposition with loss of active oxygen takes place. As stabilizers there can be used for example sodium silicate, magnesium silicate, magnesium chloride, magnesium sulfate, sodium pyrophosphate,

sodium stannate, sodium salt of ethylenediamine-tetra acetic acid.

In another form of the invention for the production of a perborate containing wash powder there is added to the slurry only the borate portion or the alkali portion of the sodium metaborate while hydrogen peroxide together with the alkali portion or conversely the borate portion of the sodium metaborate is added shortly before the spray nozzle.

Finally one can introduce into the slurry stream shortly before the nozzle all of the components of the per compound, such as the borate portion, the alkali portion and the hydrogen peroxide, separately or together as a melt, solution or suspension.

ln place of the sodium metaborate there can be used potassium metaborate, a mixture of sodium tetraborate and sodium hydroxide which forms sodium metaborate, a mixture of potassium tetraborate and potassium hydroxide which forms potassium metaborate, a mixture of boric acid and sodium hydroxide which forms sodium metaborate as well as boric acid and potassium hydroxide which forms potassium metaborate.

According to a further form of the invention it is also possible to produce a washing, bleaching and cleansing agent that contains as the bleaching agent an addition compound of sodium tetraborate and hydrogen peroxide, the so-called perborax (Na B 3 H 0 For this purpose there is simply added to the slurry to be sprayed sodium tetraborate and hydrogen peroxide is inserted as an active oxygen carrier shortly before the nozzle or there are separately or jointly introduced into the slurry stream both components shortly before the nozzle.

In place of the sodium tetraborate there can be used potassium tetraborate, a mixture of boric acid and sodium hydroxide which forms sodium tetraborate as well as a mixture of boric acid and potassium hydroxide which forms potassium tetraborate.

Unless otherwise indicated all parts and percentages are by weight.

The process of the invention will be further illustrated by the examples.

EXAMPLE I To produce a slurry the following constituents were introduced into 2,600 parts of water at C.

200 parts of Marlon A 375 (a 75 percent solution in water of sodium alkylbenzenesulfonate containing 12 carbon atoms in the alkyl group) 600 parts of neutral sodium pyrophosphate 60 parts magnesium silicate 40 parts carboxymethylcellulose 232 parts sodium metaborate (NaBO '4H,0)

400 parts anhydrous sodium sulfate The slurry obtained in this manner was treated in a spray tower in the course of about l hour. Immediately before introduction of the slurry into the spray nozzle there was uniformly added parts of hydrogen peroxide (70 percent). The temperature of the drying at the entrance to the tower was 183 C. and at the exit 93 C. The wash powder mixture obtained had a content of 2.1 l percent active oxygen material and L43 percent boron which corresponds to a sodium perborate tetrahydrate (NaBO '4H- .O) content of 20.3 percent.

EXAMPLE 2 To produce a slurry there were introduced to 2,628 parts of water at 80 C. the following constituents parts of Marlon A 375 300 parts of neutral sodium pyrophosphate 15 parts of magnesium silicate 36 parts of magnesium chloride hexahydrate 20 parts of carboxymethyl cellulose 128 parts of anhydrous sodium sulfate The slurry thus produced was introduced into a spray tower in the course of about an hour. Immediately before introduction of the slurry into the spray nozzle there was uniformly added the following mixture.

Two hundred parts of sodium tetraborate decahydrate dissolved in 180 parts of hydrogen peroxide (35 percent) to which previously there had been added two parts of sodium pyrophosphate and 0.03 part of the sodium salt of ethylenediaminetetra acetic acid. The temperature of the drying air amounted to 165 C. at the entrance and 98 C. at the exit.

The wash powder obtained had a content of 1.38 percent active oxygen and 1.25 percent boron, which corresponds to 8.73 percent perborax (Na B O-,-3H O Conventional spray drying temperatures can be used. The entrance temperature is usually between 100 and 600 C. and the exit temperature usually between 50 and 300 C. The slurry which is spray dried generally contains l5 to 95 percent solids, the balance being water.

in addition to hydrogen peroxide as the active oxygen carrier there can be used sodium peroxide or potassium peroxide.

There can be employed any conventional detergents, builders and other additives used in washing compositions.

Examples of suitable detergents are sodium, stearate (soap), sodium palmitate, potassium stearate, sodium oleate, potassium oleate, higher alkylaryl sulfonates containing 8-22 carbon atoms in the alkyl group, e.g. higher alkyl benzene sulfonates and higher alkyl phenol sulfonates. Thus there can be used sodium decyl benzene sulfonate, sodium dodecyl benzene sulfonate, potassium dodecyl benzene sulfonate, sodium keryl sulfonate, sodium nonyl benzene sulfonate, sodium decyl phenol sulfonate, potassium pentadecyl benzene sulfonate, ammonium dodecyl benzene sulfonate, triethanolamine decyl benzene sulfonate, sodium octadecyl benzene sulfonate. Other anionic detergents include nonnal and secondary higher alkyl sulfates having 8-22 carbon atoms in the alkyl residue such as sodium lauryl sulfate, potassium lauryl sulfate, sodium octadecyl sulfate, sodium coconut fatty alcohol sulfate, sodium octyl sulfate, as well as the corresponding long-chain aliphatic sulfonates, e.g. sodium octane sulfonate, sodium dodecane sulfonate, sodium tetradecane sulfonate, sodium octadecane sulfonate, potassium dodecane sulfonate, higher alkyl ether sulfates, higher alkyl glyceryl ether sulfates, higher alkylphenol polyethylene oxide sulfates, polyethylene oxide condensates with higher alkyl phenols such as isooctyl and nonyl phenol condensed with 8-22 moles of ethylene oxide, e.g. with 10 moles of ethylene oxide.

Phosphate builders can be included such as trisodium phosphate, tetrasodium pyrophosphate, sodium hexameta phosphate, tetra potassium pyrophosphate, potassium tripolyphosphate, sodium tripolyphosphate.

Conventional alkali and alkaline earth metal silicates also can be included such as sodium silicate, magnesium silicate and potassium silicate. Other conventional additives can also be present such as sodium sulfate, potassium sulfate, sodium chloride, magnesium chloride, sodium carbonate, potassium carbonate, sodium acetate, ammonium sulfate as well as carboxymethyl cellulose and its sodium and potassium salts and polyvinyl alcohol.

What is claimed is:

l. in a process for the production by spraying of an active oxygen compound containing washing, bleaching and cleansing agent which contains a detergent and as the sole active oxygen compound, a boric acid salt selected from the group consisting of sodium perborate, potassium perborate and perborax, the improvement comprising introducing at least one of the components of said active oxygen compound into an aqueous slurry of the detergent at relatively high temperature, shortly before the spray nozzle and hot spray drying the resulting mixture.

2. A process according to claim 1 wherein the slurry consists essentially of the detergent, active oxygen compound, a phosphate builder and a sulfate additive, the detergent is an anionic detergent, the slurry has a temperature of C. the entrance temperature of the spray drier is to 600 C. and

the exit temperature is 50 to 300 C.

3. A process according to claim 1 wherein the components of the active oxygen compound are introduced separately.

4. A process according to claim 1 wherein the components of the active oxygen compound are introduced together.

5. A process according to claim 1 wherein the boric acid salt is mixed into the slurry initially as a stable basic component and adding the active oxygen carrier to the slurry shortly before the spraying.

6. A process according to claim 5 wherein a stabilizer is I added to the oxygen carrier.

7. A process according to claim 1 wherein the active oxygen compound contains sodium perborate, sodium metaborate is present in the slurry and hydrogen peroxide is introduced into the slurry shortly before the spraying.

8. A process according to claim 1 wherein the active oxygen compound contains sodium perborate and the slurry contains either the borate component or the alkali component of sodium metaborate and the other of the borate or alkali component is added together with the hydrogen peroxide to the slurry shortly before the spraying.

9. A process according to claim 1 wherein the active oxygen compound contains perborax, sodium tetraborate is present in the slurry and hydrogen peroxide is introduced into the slurry shortly before the spraying.

110. A process according to claim 1 wherein the active oxygen compound contains perborax and sodium tetraborate as well as hydrogen peroxide are introduced into the slurry shortly before spraying. 

2. A process according to claim 1 wherein the slurry consists essentially of the detergent, active oxygen compound, a phosphate builder and a sulfate additive, the detergent is an anionic detergent, the slurry has a temperature of 80* C, the entrance temperature of the spray drier is 100 to 600* C. and the exit temperature is 50 to 300* C.
 3. A process according to claim 1 wherein the components of the active oxygen compound are introduced separately.
 4. A process according to claim 1 wherein the components of the active oxygen compound are introduced together.
 5. A process according to claim 1 wherein the boric acid salt is mixed into the slurry initially as a stable basic component and adding the active oxygen carrier to the slurry shortly before the spraying.
 6. A process according to claim 5 wherein a stabilizer is added to the oxygen carrier.
 7. A process according to claim 1 wherein the active oxygen compound contains sodium perborate, sodium metaborate is present in the slurry and hydrogen peroxide is introduced into the slurry shortly before the spraying.
 8. A process according to claim 1 wherein the active oxygen compound contains sodium perborate and the slurry contains either the borate component or the alkali component of sodium meta borate and the other of the borate or alkali component is added together with the hydrogen peroxide to the slurry shortly before the spraying.
 9. A process according to claim 1 wherein the active oxygen compound contains perborax, sodium tetraborate is present in the slurry and hydrogen peroxide is introduced into the slurry shortly before the spraying.
 10. A process according to claim 1 wherein the active oxygen compound contains perborax and sodium tetraborate as well as hydrogen peroxide are introduced into the slurry shortly before spraying. 